1. Technical Field
The present invention relates to a liquid ejecting apparatus. More specifically, the present invention relates to a heating channel unit mounted to a liquid ejecting head for heating liquid flowing in a liquid channel of a head.
2. Related Art
One type of liquid ejecting head used in a liquid ejecting apparatus currently known in the art comprises an ink jet recording head (hereinafter, referred to as a recording head) which is mounted in an ink jet printer. The recording head is capable of ejecting a liquid ink onto a recording or target medium, such as a piece of paper or other type of recording sheet, during a recording or printing process. In addition to being used in ink jet printers, liquid ejecting heads are also used for ejecting various functional liquids such as a coloring material used in a color filter of liquid crystal displays, organic material used in an organic electroluminescence (EL) displays, and electrode material used for forming an electrodes.
Recently, a light curing ink has been used to print images. The light curing ink is cured by irradiating energy in the ink using a light such as an ultraviolet ray. The light curing ink is cured by irradiating light onto a recording medium having a poor ink absorbency in order to record an image. One difficulty in using the light curing ink, however, is that the light curing ink has a viscosity higher than general ink. Thus, in order to eject the light curing ink from the liquid ejecting head, the viscosity must be reduced.
The curing sensitivity of the light curing ink also depends on the temperature of the ink. More specifically, the light curing sensitivity is decreased at low temperatures and increased at high temperatures. In order to increase the light curing sensitivity, a liquid ejecting head for heating the light curing ink using a heating unit has been developed, such as in, for example, Japanese Patent Applications JP-A-09-141892 and JP-A-2003-011349.
One difficulty with these configurations, however, is that the heating unit is added to the outer surface of the liquid ejecting head, where the ink flowing in the head channel is heated by the heat of the heating unit. In this case, in order to heat the ink from room temperature to a temperature (for example, 40° C.) suitable for the ejection, the heating unit must heath the outer surface of the liquid ejecting to a higher temperature, increasing the amount of power consumed by the recording head, and consequently, shortening the life span of the recording head.